1. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Fundamentals of Anatomy & Physiology SIXTH EDITION Frederic H. Martini PowerPoint ® Lecture Slide Presentation prepared by Dr. Kathleen A. Ireland, Biology Instructor, Seabury Hall, Maui, Hawaii Chapter 25, part 2 Metabolism and Energetics

2. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings SECTION 25-3 Lipid Metabolism

3. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Lipolysis Lipids broken down into pieces that can be converted into pyruvate Triglycerides are split into glycerol and fatty acids Glycerol enters glycolytic pathways Fatty acids enter the mitochondrion Lipid catabolism

4. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Beta-oxidation Breakdown of fatty acid molecules into 2-carbon fragments Enter the TCA Irreversible Lipids and energy production Cannot provide large amounts in ATP in a short amount of time Used when glucose reserves are limited Lipid catabolism

5. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 25.9 Beta Oxidation Figure 25.9

6. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 25.9 Beta Oxidation Figure 25.9

7. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Almost any organic molecule can be used to form glycerol Essential fatty acids cannot be synthesized and must be included in diet Linoleic and linolenic acid Lipid synthesis (lipogenesis)

8. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 25.10 Lipid Synthesis Figure 25.10

9. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings 5 types of lipoprotein Lipid-protein complex that contains large glycerides and cholesterol Chylomicrons Largest lipoproteins composed primarily of triglycerides Very low-density lipoproteins (VLDLs) contain triglycerides, phospholipids and cholesterol Lipid transport and distribution

10. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings 5 types of lipoprotein (continued) Intermediate-density lipoproteins (IDLs) Contain smaller amounts of triglycerides Low-density lipoproteins (LDLs) Contain mostly cholesterol High-density lipoproteins (HDLs) Equal amounts of lipid and protein Lipid transport and distribution

11. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Enzyme that breaks down complex lipids Found in capillary walls of liver, adipose tissue, skeletal and cardiac muscle Releases fatty acids and monglycerides Lipoprotein lipase

12. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 25.11 Lipid Transport and Utilization Figure 25.11a

13. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 25.11 Lipid Transport and Utilization Figure 25.11b

14. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings SECTION 25-4 Protein Metabolism

15. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings If other sources inadequate, mitochondria can break down amino acids TCA cycle removal of the amino group (-NH 2 ) Transamination – attaches removed amino group to a keto acid Deamination – removes amino group generating NH 4 + Proteins are an impractical source of ATP production Amino acid catabolism

16. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 25.12 Amino Acid Catabolism Figure 25.12

17. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 25.12 Amino Acid Catabolism Figure 25.12a

18. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 25.12 Amino Acid Catabolism Figure 25.12b

19. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 25.12 Amino Acid Catabolism Figure 25.12c

20. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Essential amino acids Cannot be synthesized by the body in adequate supply Nonessential amino acids Can be synthesized by the body via amination Addition of the amino group to a carbon framework Protein synthesis

21. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 25.13 Amination Figure 25.13

22. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 25.14 Figure 25.14 A Summary of the Pathways of Catabolism and Anabolism

23. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings SECTION 25-5 Nucleic Acid Metabolism

24. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Nuclear DNA is never catabolized for energy RNA catabolism RNA molecules are routinely broken down and replaced Generally recycled as nucleic acids Can be catabolized to simple sugars and nitrogenous bases Do not contribute significantly to energy reserves Nucleic acid metabolism

25. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Most cells synthesis RNA DNA synthesized only when preparing for division Nucleic acid synthesis